NBC News spoke with Bakr hours later and learned he had survived the blast. He explained that when the explosion interrupted the earlier Skype interview he had rushed out to his neighbor's house to make sure everyone was fine. Bakr said one child was injured but he says the child is doing well now.

Earlier, Bakr mentioned he had been in the same house where Marie Colvin, an American working for Britain's Sunday Times, and French photographer Remi Ochlik, were killed Wednesday.

'Urgent' need for help
He said the international community must take action.

"It is urgent that you have humanitarian corridor in Syria," he said. "This could save the lives of a lot Syrians."

Bakr criticized Russia and China, which have blocked efforts to pressure Assad's regime in the United Nations.

"(On one hand) they are talking about preventing ... external intervention in Syria, and on other hand they are sending the weapons and the mercenaries to Syria to support Assad's crimes," he told NBC News.

Neubert told msnbc.com after the conversation that NBC colleagues had been calling their contacts in Syria to try to find out if Bakr was OK.

"It's so difficult to reach anyone there. It's proving almost impossible to clarify what happened, but we are endeavoring to do so," she said.

As government troops continued to pound rebel-held neighborhoods in Homs, thousands of people in dozens of towns across Syria staged anti-regime protests under the slogan: "We will revolt for your sake, Baba Amr."

Meanwhile, more than 70 countries were taking part in Friday's "Friends of Syria" meeting in Tunisia, which is expected to press President Bashar Assad to agree to a cease-fire and allow for humanitarian aid to reach the areas that have been hardest-hit by his security forces.

American, European and Arab officials have said the group would likely impose harsher sanctions if Assad rejects the cease-fire, and predicted the regime's opponents would grow stronger if Assad remained in power.

The U.N. estimated in January that 5,400 people had been killed in the conflict in 2011.

Hundreds more have died since. Syrian activists say the death toll is more than 7,300. Overall figures cannot be independently confirmed because Syria has prevented most media from operating inside the country.

Assad's security forces blames the uprising on Islamic extremists and armed gangs. The opposition, boosted by army defectors, has increasingly taken up arms against the regime.